The traditional safety distance model based on the braking process is inadequate for scenarios where the adhesion coefficient varies. This research presents a safety distance model that takes into account the real-time fluctuations in the adhesion coefficient during the braking process. The proposed safety distance model is the basis for a three-level control strategy aimed at ensuring the safety and stability of the car-following process. A simulation is conducted to model the variation of the road’s adhesion coefficient during car braking. The experimental results, obtained for various initial adhesion coefficients and speeds, demonstrate that the precision of the safety distance calculated is improved by a minimum of 14.99% when compared to the traditional safety distance. Furthermore, the simulation results of the car-following process of a motorcade consisting of five cars provide evidence of the safety and stability of the suggested model.
Risk prediction is an important task to ensuring the driving safety of railway trams. Although data-driven intelligent methods are proved to be effective for driving risk prediction, accuracy is still a top concern for the challenges of data quality which mainly represent as the unbalanced datasets. This study focuses on applying feature extraction and data augmentation methods to achieve effective risk prediction for railway trams, and proposes an approach based on a self-adaptive K-means clustering algorithm and the least squares deep convolution generative adversarial network (LS-DCGAN). The data preprocessing methods are proposed, which include the K-means algorithm to cluster the locations of trams and the extreme gradient boosting recursive feature elimination based feature selection algorithm to retain the key features. The LS-DCGAN model is designed for sparse sample expansion, aiming to address the sample category distribution imbalance problem. The experiments implemented with the public and real datasets show that the proposed approach can reach a high accuracy of 90.69%, which can greatly enhances the tram driving safety.
Recent advancement of large language models (LLMs) has led to significant breakthroughs across various tasks, laying the foundation for the development of LLM-based speech translation systems. Existing methods primarily focus on aligning inputs and outputs across modalities while overlooking deeper semantic alignment within model representations. To address this limitation, we propose an Adaptive Inner Speech-Text Alignment (AI-STA) method to bridge the modality gap by explicitly aligning speech and text representations at selected layers within LLMs. To achieve this, we leverage the optimal transport (OT) theory to quantify fine-grained representation discrepancies between speech and text. Furthermore, we utilize the cross-modal retrieval technique to identify the layers that are best suited for alignment and perform joint training on these layers. Experimental results on speech translation (ST) tasks demonstrate that AI-STA significantly improves the translation performance of large speech-text models (LSMs), outperforming previous state-of-the-art approaches. Our findings highlight the importance of inner-layer speech-text alignment in LLMs and provide new insights into enhancing cross-modal learning.
Reliable manual annotations for Vietnamese logistics calls are scarce, and telephone channel degradation compounds errors in business-critical entities. Existing adaptation methods typically optimize aggregate transcription accuracy, use uniform token losses, or apply a fixed training schedule; few control parameter updates, entity-level supervision, and sample order together when labels are noisy. We address this problem by combining low-rank adaptation (LoRA), token-level entity-weighted cross-entropy, and validation feedback curriculum learning for Whisper-large-v3. A joint acoustic–semantic score ranks samples by signal quality, sequence length, entity density, and linguistic rarity. The curriculum boundary expands only after the validation loss improves. On 20,317 in-domain training utterances, the complete system achieves a word error rate (WER) of 0.0735 and a mean exact match entity accuracy of 92.1%. Compared with vanilla LoRA, it reduces WER by 4.92% and raises entity accuracy from 85.3% to 92.1%. Ablation results show that curriculum pacing and entity weighting each contribute to the final performance.